Its safer than the average 1970s car but I wouldn't want to have an accident in it vs a modern car. Besides airbags it lacks, ABS, seatbelt pretensioners, UHSS structure... the list is long. That seatbelt alone are not going to prevent your head from impacting the steering wheel.
https://www.youtube.com/watch?v=BCA-GuE0mUA
https://www.youtube.com/watch?v=lgegEGQAsIk
http://www.w123.dk/index.htm?http://www.w123.dk/w123_w123Sikkerhed.htm